261 resultados para Female


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In a recent paper, we demonstrated that male-female genetic relatedness determines male probability of paternity in experimental sperm competition in the Peron's tree frog (Litoria peronii), with a more closely related male out-competing his rival. Here, we test the hypothesis that a male-male difference in siring success with one female significantly predicts the corresponding difference in siring success with another female. With male sperm concentration held constant, and the proportion of viable sperm controlled statistically, the male-male difference in siring success with one female strongly predicted the corresponding difference in siring success with another female, and alone explained more than 62 per cent of the variance in male-male siring differences. This study demonstrates that male siring success is primarily dictated by among-male differences in innate siring success with less influence of male-female relatedness.

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There is increasing theoretical and empirical evidence that genetic compatibility among partners is an important determinant of fertilization success and offspring viability. In amphibians, females often actively choose partners from among a variety of males and polyandry is common. Genetic compatibility among partners may therefore be an important determinant of fertilization success and offspring viability in some amphibians. Amphibians also show some of the highest levels of genetic differentiation among neighbouring populations known in vertebrates, and as such, populations may have evolved different co-adapted gene complexes. This means that offspring from among-population crosses may have reduced fitness. It is therefore essential to understand to what extent crossings between and within populations may interfere with successful fertilization and offspring viability. Here, we test whether crossing individuals within and between two different populations of the Australian Peron's tree frog (Litoria peronii) using artificial fertilizations affect fertilization success and offspring viability. Fertilization success per se is strongly influenced by male identity, which is likely to depend at least to some extent on the experimental procedure (e.g. resulting in variation in sperm number per ejaculate), whereas there was no fertilization effect of female identity. More importantly, male and female identity, independently of each other, explained significant variation in offspring viability, whereas no such effect could be linked to population of origin. Thus, our experiments suggest that crossing populations may not always be the most significant factor affecting fertilization success or offspring viability, but may be more influenced by the genetic quality or the genetic compatibility of partners.

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It is well established in genetic epidemiology that family history is an important indicator of familial aggregation of disease in a family. A strong genetic risk factor or an environmental risk factor with high familial correlation can result in a strong family history. In this paper, family history refers to the number of first-degree relatives affected with the disease. Cui and Hopper (Journal of Epidemiology and Biostatistics 2001; 6: 331-342) proposed an analytical relationship between family history and relevant genetic parameters. In this paper we expand the relationship to both genetic and environmental risk factors. We established a closed-form formula for family history as a function of genetic and environmental parameters which include genetic and environmental relative risks, genotype frequency, prevalence and familial correlation of the environmental risk factor. The relationship is illustrated by an example of female breast cancer in Australia. For genetic and environmental relative risks less than 10, most of the female breast cancer cases occur between the age of 40 and 60 years. A higher genetic or environmental relative risk will move the peak of the distribution to a younger age. A more common disease allele or more prevalent environmental risk factor will move the peak to an older age. For a proband with breast cancer, it is most likely (with probability ge80%) that none of her first-degree relatives is affected with the disease. To enable the probability of having a positive family history to reach 50%, the environmental relative risks must be extremely as high as 100, the familial correlation as high as 0.8 and the prevalence as low as 0.1. For genetic risk alone, even the relative risk is as high as 100, the probability of having a positive family history can only reach about 30%. This suggests that the environmental risk factor seems to play a more important role in determining a strong family history than the genetic risk factor.

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Genetic and environmental influences on variation in balance performance were measured in 93 monozygous and 83 dizygous female twin pairs aged 21–82 years (mean age, 50.5 years) in Melbourne, Australia, between 1999 and 2003. The authors administered clinical (Lord's Balance Test and Step Test) and laboratory tests of static and dynamic balance from the Chattecx Balance System with and without distractor tasks. The authors conducted factor analysis and estimated genetic and environmental variance components and heritability (defined as additive genetic variance as a proportion of all variance, after adjustment for age) using a multivariate normal model with the statistical package FISHER. Three factors were identified and adjusted for age. Heritability was 46% (standard error (SE), 9) for the "sensory balance tests" factor and 30% (SE, 9) for the "static and dynamic perturbations" factor. For both factors, the remaining variance was attributed to unique environmental effects. There was no evidence that genetic factors influenced variation in the "dynamic weight shift tests" factor, with environmental effects shared by twins accounting for 38% (SE, 7) of variance. Neither genetic nor environmental proportions of variance differed significantly between twin subgroups by age (≤50/>50 years). An age-related decline in performance measures was found across the whole sample. These results imply that balance impairments may have a heritable element.

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Looked at from a global perspective, sports are mostly male preserves. Those played by women seldom attract a large spectatorship and the numerous at-ground viewers of men’s play mostly are men. An exception is Australian Rules Football (AFL), a male sport that since the 19th century has drawn a considerable female following, with women accounting for about half of the ‘live’ crowds. From single-person and focus group interviews conducted with female AFL fans, we examine how women voice their support for a sport characterised by hyper-masculinity in players’ on-field and off-field behaviours, in the organisation and control of the sport, and in the ‘natural’ authority credited to men’s voices in commentary and interpretation of it. Given their marginalisation in AFL and in sports generally, what do women fans gain from their avid support of AFL and how does this influence the construction of their identities as women? We examine these issues from a perspective supporting the idea of multiple, fragmented identities.

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Consistent with FIFA president Sepp Blatter’s proclamation that the future of football is female, the Australian Football League (AFL) has instituted a range of initiatives in an attempt to present a ‘female friendly’ face and garner women’s support for the national game. Given the large number of women who follow the AFL, especially in comparison to other football codes nationally, it’s worth considering the motivations behind the AFL’s tactics. To what extent does what the AFL think women want correlate with women supporters’ experiences and realities of being a football fan? This paper presents findings from semi-structured and focus group interviews with female AFL fans to gauge their perceptions of being an Australian rules football supporter and its impact on their lived experiences and sense of self. The responses of women supporters are critically assessed in order to contemplate how women negotiate gender identity through their support of a male dominated sport. As well as offering insights into the role gender plays in leisure pursuits such as sport spectatorship, this paper considers how femininity and masculinity might be contested and/or remade through the practice of following football in the Australian context. By demonstrating the range and diversity of women’s experiences, this research has the capacity to generate alternative imaginings of fanship and sporting community beyond gender stereotypes.

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This study examines the general impressions and blame attributions of Trinidadian university students in cases of sexual assault. Participants were 132 female students from the University of the West Indies, Faculty of Social Sciences. Each respondent read one of four sexual assault scenarios, in which victim and perpetrator gender were varied. Participants' impressions of the incident, opinions about each party's behaviour, blame attributions, attitudes about reporting the incident to the police, desired outcome, and their reasons for these were then assessed. Consistent with Burt's rape myth theory, the qualitative and quantitative results showed a tendency for participants to attribute an internal locus of control to female victims, and to blame them more than males. Although same sex events evoked significantly more emotional and disgust-related reactions, these reactions did not translate into different seriousness scores, or different ideas about whether the victim should report the incident to the police. Although respondents showed an ability to separate their initial reactions from their attitudes about the legal status of the event, many of the response patterns indicated gender role biases on the part of these future professionals.

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This thesis examined the aetiology of female sexual dysfunction (FSD) and a model to represent sexual function. Relationship factors were the main predictor of sexual function for women with FSD. A circular model of sexual response represented women's sexual experience for those with FSD and those who did not have FSD. In order to illustrate the role of family emotional involvement in children's development of psychological disorders the portfolio presents and explores four case studies.

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The ovarian follicles and oviducal glands have structural organisations similar to other chondrichthyans. Sperm are stored in the oviducal gland of all maturing and mature animals throughout the year and throughout pregnancy. Microscopic features of the uterine epithelium suggest nutrients are supplied to developing embryos without placenta formation.

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This thesis argues that a sense of personal power, agency and self-worth can be regained through art practice and will cite examples of this process by artists and others who are outside the parameters of hegemony. The author's experience as a female artist is discussed within the context of historical and contemporary art practices that focus mainly on representations of the female nude, and therefore follows the notion that the personal is political.